# George Kingsley Zipf

George Kingsley Zipf

1917 photograph from the 1919 Annual of the Freeport High School, Freeport, Illinois
Born January 7, 1902
Freeport, Illinois
Died September 25, 1950 (aged 48)
Newton, Massachusetts
Nationality American
Fields Statistics, linguistics
Alma mater Harvard College
Known for Zipf's law

George Kingsley Zipf (;[1] 1902–1950), was an American linguist and philologist who studied statistical occurrences in different languages.[2]

Zipf earned his bachelors, masters, and doctoral degrees from Harvard University, although he also studied at the University of Bonn and the University of Berlin.[2] He was Chairman of the German Department and University Lecturer (meaning he could teach any subject he chose) at Harvard University.[2] He worked with Chinese languages and demographics, and much of his effort can explain properties of the Internet, distribution of income within nations, and many other collections of data.[3]

## Zipf's law

George Kingsley Zipf is the eponym of Zipf's law, which states that while only a few words are used very often, many or most are used rarely,

$P_n \sim 1/n^a$

where Pn is the frequency of a word ranked nth and the exponent a is almost 1. This means that the second item occurs approximately 1/2 as often as the first, and the third item 1/3 as often as the first, and so on. Zipf's discovery of this law in 1935 was one of the first academic studies of word frequency.[4]

Although he originally intended it as a model for linguistics, Zipf later generalized his law to other disciplines. In particular, he observed that the rank vs. frequency distribution of individual incomes in a unified nation approximates this law, and in his 1941 book, "National Unity and Disunity" he theorized that breaks in this "normal curve of income distribution" portend social pressure for change or revolution.

## Bibliography

• Zipf, George Kingsley (1932): Selected Studies of the Principle of Relative Frequency in Language. Cambridge (Mass.).
• (1935): The Psycho-Biology of Language. Cambridge (Mass.).
• (1941): National unity and disunity
• (1946): The P1 P2/D Hypothesis: On the Intercity Movement of Persons. American Sociological Review, vol. 11, Dec, pp. 677
• (1949): Human behavior and the principle of least effort

## References

1. ^ Leitch, Matthew (2010), A Pocket Guide to Risk Mathematics: Key Concepts Every Auditor Should Know, John Wiley & Sons, p. 62, ISBN 9780470971468.
2. ^ a b c "Zipf Dies After 3 - Month Illness", The Harvard Crimson, September 27, 1950.
3. ^ Saichev, A. I.; Malevergne, Yannick; Sornette, Didier (2009), Theory of Zipf's Law and Beyond, Lecture notes in economics and mathematical systems 632, Springer, p. 1, ISBN 9783642029462.
4. ^ Baayen, R. Harald (2002), Word Frequency Distributions, Text, Speech and Language Technology 18, Springer, p. 13, ISBN 9781402009273.